Authorities said Officer Michael Chesna, a five-year veteran of the Weymouth Police Department, was responding to a report of an erratic driver near South Shore Hospital shortly after 7:30 a.m. on Sunday.

Chesna, 42, saw the suspect, whom police have identified as 20-year-old Lopes, allegedly vandalizing a home on Burton Terrace.

Chesna approached Lopes with his gun drawn and attempted to arrest him, Norfolk County Assistant District Attorney Greg Connor said at a press conference Sunday.

Emanuel Lopes is in police custody, accused of shooting a Weymouth police officer and an innocent bystander on Sunday.
Photo credit: NBC10 Boston

"Lopes then attacked Officer Chesna, it is believed, with a large stone, striking him in the head, and Officer Chesna fell to the ground," Connor said.

According to authorities, Lopes grabbed Chesna's gun and shot him multiple times in the head and chest. Chesna was taken to South Shore Hospital, where he was pronounced dead.

ADA Speaks on Shooting That Killed Officer, Elderly Woman

Norfolk County Assistant District Attorney Greg Connor spoke Sunday afternoon on the ongoing investigation into a shooting that killed Weymouth Police Officer Michael Chesna and an unidentified elderly woman.

(Published Monday, July 16, 2018)

Additional responding officers chased Lopes through the neighborhood, where he allegedly discharged Chesna's gun at least three times, killing an elderly woman in her home. Her name has not been released pending notification of family.

Police reportedly shot Lopes in the leg. He is expected to survive and will be arraigned Monday on two counts of murder. It's unclear if he will be arraigned in the hospital or in a courtroom. It's also unclear if he has an attorney.

Officer, Innocent Bystander Dead in Weymouth

Officer Michael Chesna, 42, and a woman whose name is yet to be released, are dead. They were allegedly shot by 20-year-old Emanuel Lopes early Sunday.

(Published Sunday, July 15, 2018)

State police detectives assigned to the Norfolk County District Attorney's Office are continuing to investigate the incident.

"On behalf of the Massachusetts State Police I offer our deepest condolences to the family of Officer Chesna, the family of the Weymouth woman who was also killed, and the Weymouth Police Department," Col. Kerry Gilpin, superintendent of the Massachusetts State Police, said in a statement.

"I am deeply saddened to learn of the passing of Officer Chesna and an innocent bystander today and my thoughts and prayers are with their families, loved ones and the @WeymouthPD after this tragic loss," Massachusetts Gov. Charlie Baker said on Twitter Sunday. The Commonwealth is forever grateful for the courageous men and women who risk their lives to serve and protect our communities every single day.

New England Patriots owner Robert Kraft stopped by the Weymouth Police Department on Sunday to share his condolences. "It's just terrible," he said.

WATCH: Procession for Slain Weymouth Officer

Police formed a procession as the body of slain Weymouth, Mass. police officer Michael Chesna was moved from South Shore Hospital to the state's medical examiner's office.

(Published Sunday, July 15, 2018)

Chesna, an Army combat veteran, is survived by his wife and two young children. Monday would have been his sixth anniversary as an officer with the Weymoth Police Department.

Weymouth Police Chief Richard Grimes described Chesna Sunday as a "family man" who "always had a kind and good attitude."

"He was one of those people who truly sought this job, was fortunate enough to get it, and very much appreciated it," Grimes said.

Chesna is the second officer to be killed in a shooting in Massachusetts this year. Yarmouth Police K-9 Sgt. Sean Gannon was shot and killed by a man who was hiding in an attic in April. His K-9 partner Nero was recently cleared for normal activity.